81025577982 has 48 divisors (see below), whose sum is σ = 186116341632. Its totient is φ = 25430863680.

The previous prime is 81025577903. The next prime is 81025578031. The reversal of 81025577982 is 28977552018.

81025577982 is a `hidden beast` number, since 8 + 1 + 0 + 2 + 557 + 7 + 9 + 82 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1941613 + ... + 1982904.

It is an arithmetic number, because the mean of its divisors is an integer number (3877423784).

Almost surely, 2^81025577982 is an apocalyptic number.

81025577982 is an abundant number, since it is smaller than the sum of its proper divisors (105090763650).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81025577982 is a wasteful number, since it uses less digits than its factorization.

81025577982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3924593 (or 3924590 counting only the distinct ones).

The product of its (nonzero) digits is 2822400, while the sum is 54.

The spelling of 81025577982 in words is "eighty-one billion, twenty-five million, five hundred seventy-seven thousand, nine hundred eighty-two".